History Corner

Because a smelter was so important to the success of mining operations in the Seven Devils Mining District, it was an almost constant subject of news and conjecture in area newspapers in 1898.

By the end of July, the smelter manager sued the owner for unpaid salary and the operation was again under attachment. The July 28 Signal blasted mine owner Isaac Blake with the headline: “The Year’s Results Vindicate the Protests against the Illegitimate Methods, Made by the Signal at the Opening of the Era of Folly – Has Isaac Left the Nest and Flown? – Past Pleas for Honest Operations in Seven Devils Justified by Present Facts – Sad Trail of Blake’s Brilliant Botch – Attachments, Debts, Disgrace, He Faulted Interest, Unmet Obligations – Folly, Fizzle, Failure.”

Editor Robert Lockwood called Isaac Blake’s schemes “a farce,” adding that the production of copper might have been successful “if the money Isaac has squandered had been applied with sense and business ability.”

Near the end of August, the Salubria Citizen noted that three different outfits had tried to make the smelter work, but now it was shut down, probably for good.

In the Signals September 29 issue, Lockwood commented again on the smelter: “Up to the present writing the scheme has not proved a howling success and the consequences are that Cuprum is now a deserted village and quite a number of confiding people are left out in the cold with worthless investments and buildings. The town is made up of a number of small, well-built houses, either wood or logs, and the company offices and smelter.”

Another description of Cuprum in the Signal said: “Quite a little town, named Cuprum, has grown up near the smelter. It has a store, post office, two saloons and quite a number of substantial dwellings.”

By the end of 1898 everyone had concluded that the Cuprum smelter was a failure.

Headline in the Weiser Signal, December 1, 1898: “Mr. John Glass, General Manager for the Northwest Mining Company Has Made His Headquarters at Cuprum.” Mr. Glass said he intended to move all of their buildings, including the smelter, to “Little Bar” at the foot of the Kleinschmidt Grade. He moved the smelter in early 1899.

The smelter’s failure

The smelter at Cuprum was almost certainly fairly small and elementary and faced a number of challenges that might have proven fatal, even for a bigger, more sophisticated smelter. The biggest challenge was the ore itself. Seven Devils ore was often called “Refractory” or “Rebellious” because it was difficult to extract the copper. Although promoters always touted Seven Devils ore as being “the richest in the world,” the ore was actually unusually high in sulfur-rich minerals and often contained more sulfur and iron than copper, which is the worst possible ratio for smelting with a small, elementary smelter like the one at Cuprum.

Smelting involved adding a flux and applying intense heat to the ore. During that process, furnaces tended to “choke” with sulfur dioxide — a very toxic, colorless gas. It’s one of the major gases released when sulfide minerals like Seven Devils ores are heated. Choking is almost certainly what the newspapers meant when they said the smelter “froze up.”

High-sulfur ores release enormous amounts of sulfur dioxide when heated. Smelters “choked” when sulfur dioxide and furnace gases could no longer escape fast enough, causing the furnace to lose draft and suffocate the fire. Smoke particles, fumes and dust fell back into the melt. The furnace cooled, slag “froze,” and matte stopped forming properly. Workers had to shut down, dig out the furnace, and restart — a huge loss of time and money.

When a smelter choked, the matte produced was contaminated and of low quality / value.

If the smelter chimney of the Cuprum smelter was similar in size to the Landore smelter that was built later, it wasn’t very tall –at least not compared to the big, industrial smelters back east – so this would have contributed to less draft and choking.

I’ve never seen any reference to “roasting piles” in the Seven Devils Mining District, but it was desirable (maybe even necessary) to “roast” high sulfide ores before smelting to reduce the sulfur dioxide content and prevent choking. This involved piling ore on a bed of wood, which was ignited and allowed to slow-burn for several weeks at a temperature hot enough to oxidize the sulfides but not hot enough to melt the ore. If this wasn’t done, it’s no wonder the Cuprum smelter never worked right.

The Council Valley Museum will be opening near the end of this month and volunteers are badly needed. We especially need folks who can do a weekly 3-hour shift, but we also need anyone who can fill in occasionally. Please contact me if you can help.